Role of Stress Protein on Bacterial Infection

所有生物体对不利条件的反应都是通过一组被称为应激蛋白的蛋白质的快速和瞬时加速合成来实现的。对于病原菌来说，巨噬细胞的胞内环境是最恶劣的环境之一。因此，吞噬细胞中的细菌可能通过表达应激蛋白和PRO蛋白来响应敌意刺激。Teiris可能使胞内细菌在吞噬细胞中的存活处于优势地位。为了阐明细菌应激蛋白在巨噬细胞存活和毒力表达中的作用，我们研究了小肠结肠炎耶尔森菌和单核细胞增生性李斯特菌吞噬巨噬细胞后的应激反应及其应激蛋白在巨噬细胞中的作用。结果表明：(1)肠结肠炎耶尔森菌gsrLAMBDA对巨噬细胞的细胞外环境应激和细胞内吞噬应激均具有保护作用。GsrLAMBDA编码一个49.5 kDa的碱性蛋白，是一种周质蛋白。(2)巨噬细胞吞噬诱导GsrA应激蛋白表达。(3)单核细胞增生性李斯特菌在没有应激蛋白诱导的情况下也能在巨噬细胞中生长。(4)克隆了单核细胞增多性李斯特氏菌的dnaK基因，并对其进行了分子生物学分析，以了解应激蛋白dna K在单核细胞增生性李斯特菌细胞内存活中的作用。(5)DNAK在巨噬细胞中对巨噬细胞的存活没有很大的贡献，但参与了吞噬过程。从这些结果推测，除了物种特有的机制外，胁迫蛋白的共同机制可能有助于细菌病原菌esis的表达。

All organisms respond to unfavorable conditions such as stressful environment by the rapid and transient acceleration in the synthesis of a group of proteins called the stress proteins. For pathogenic bacteria, the intracellular environment of macrophages is one of the most hostile environments. Therefore, the bacteria in the phagocytes may respond to the hostile stimuli by the expression of the stress proteins, and those pro. teiris may put the intracellular bacteria at advantages in the survival in the phagocytes. To elucidate the role of bacterial stress protein on the survival in the macrophages and expression of virulence, we studied the stress response and the role of stress proteins of Yersinia enterocolitica and Listeria monocytogenes within macrophages after phagocytosis. The results are as follows ; (1) The Y.enterocolitica gsrLAMBDA was identified as essential for protecting cells under both extracellular environmental stress and intracellular stress in macrophages due to phagocytosis. The gsrLAMBDA encodes a basic 49.5 kDa protein which is a periplasmic protease. (2) The GsrA stress protein was induced by macrophage phagocytosis. (3) L.monocylogenes could grow in macrophages without the induction of stress proteins. (4) The dnaK gene was cloned and subjected to the molecular analysis to understand the role of stress protein DnaK for intracellular survival of L.monocylogenes . (5) The DnaK does not largely contribute to the survival of L.inonocytogenes in macrophage cells but is involved in the step of the phagocytosis. From these results, it is speculated that common mechanisms with the stress proteins would contribute to the expression of the bacterial pathogen esis besides the species-specific mechanisms.